There exist conventionally print shops which produce printed products on the basis of requests from customers such as private users and companies. A print shop receives print data (original) and instructions of style, number of copies, and delivery date, creates a printed product, and delivers it to the customer. The operation in the print shop is done by using a large-scale printing apparatus such as an offset plate-making printing press.
Along with the recent increase in speed and image quality of an electrophotographic printing apparatus or inkjet printing apparatus, commercial print businesses (print services) called “copy service”, “printing service”, and “Print On Demand (POD) center” capable of output/delivery in a short time have also emerged.
A user takes directly or sends by mail, to a print shop that provides the above-described print services, a document recorded on paper or electronic medium (e.g., FD, MO, or CD-ROM) and a print instruction (order instruction) containing the number of copies, binding style, and delivery date of the document, thereby requesting printing of the print shop (entry).
A print system that allows print order placement/reception through the Internet or an intranet has also been put into practical use. To use this print system, the user accesses from the computer of his/her own to a homepage provided by the print shop, fills a print request form with order sender information (e.g., the address of the recipient) and necessary items such as the print style and number of copies, and transmits the form together with the document file. With this operation, the user can place an order for printing of the document file.
Upon receiving the request from the user, the print shop creates a print instruction and schedules print processing. In accordance with the created schedule, printing is executed by a printer connected to a work computer. A finishing apparatus executes binding. The created printed product is delivered to the customer, and the operation is ended.
Such a print shop that executes print processing consigned by a user often deals with a job that produces a document (printed product) using a plurality of types of paper in a single document. When such a document is output by using a single output device, paper types set in the paper feed stages of the output device (e.g., printer) do not suffice, and cassette exchange frequently occurs at a high probability.
Japanese Patent Laid-Open No. 2002-108596 discloses a technique to reduce load in this cassette exchange. In Japanese Patent Laid-Open No. 2002-108596, a priority is given to each paper type. The order of paper types to be set is decided in accordance with the priorities. The paper type is exchanged in accordance with the to-be-set paper type order decided on the basis of the priorities, thereby decreasing the number of times of exchange.
In the Japanese Patent Laid-Open No. 2002-108596, a priority is set for each paper type, and print processing is executed once per paper type. For example, a print job which should be processed in an order of paper types A, B, C, D, A, and C is processed once per paper type, thereby decreasing the number of times of paper type exchange.
However, in a work flow system, the process schedule is created in advance, as described above. Hence, the processing order cannot be changed. As a result, even when Japanese Patent Laid-Open No. 2002-108596 is applied to the work flow system, the number of times of paper type exchange cannot be decreased. Hence, a control method that can be applied to a work flow system and reduces the number of times of paper type exchange without changing the processing order is demanded.